Pacific Treefrog (Pseudacris regilla)
Order Anura, Family Hylidae (Treefrogs), Genus Pseudacris. This species is part of the chorus frog group, known for their vocal abilities and small size.
Species
Pacific Treefrog (Pseudacris regilla)
Family
Order Anura, Family Hylidae (Treefrogs), Genus Pseudacris. This species is part of the chorus frog group, known for their vocal abilities and small size.
Size
Adult SVL (Snout-to-Vent Length) is typically 2.5 to 5 cm (1 to 2 inches). Females are generally larger than males. They are lightweight, typically weighing only a few grams.
Conservation
IUCN Status: Least Concern. Populations are generally stable and they are among the most common amphibians in their range, though they face local threats from habitat loss and pollutants.
Description
The Pacific Treefrog is the iconic voice of the West Coast. This tiny gymnast is often found perched on leaves, blending perfectly into the greenery. Its ability to shift between vibrant greens and earthy browns makes it a master of disguise. Seeing one tucked into a garden leaf, like in this image, is a highlight for any backyard naturalist.
Key Features
Presence of a dark eye stripe (mask), small toe pads, lime green or brown dorsal color, and a small body size under 2 inches.
Physical Description
A small, slender frog with a rounded snout and large, prominent eyes. The limbs are well-proportioned for both hopping and climbing, featuring small but distinct toe pads (disks). The body is somewhat compact, and the tympanum is small but visible behind the eye mask.
Skin Texture & Coloration
Skin is generally smooth but can appear slightly moist or granular. Coloration is highly variable, ranging from bright lime green (as seen here) to bronze, tan, or grey. A signature dark brown or black 'eye mask' stripe extends from the tip of the snout, through the eye, to the shoulder. The belly is usually creamy white.
Distinguishing Features
The most definitive field mark is the dark 'mask' stripe through the eye. Additionally, they have small adhesive toe pads and often exhibit a 'Y' or 'V' shaped mark between the eyes (though not always visible). Their ability to change color from green to brown in minutes based on humidity and temperature is distinct.
Habitat
Extremely versatile; found in forests, meadows, chapparal, and urban gardens. They require slow-moving water or ponds for breeding but are highly terrestrial/arboreal otherwise. They are frequently found on low-lying vegetation and shrubs.
Geographic Range
Native to the Pacific coast of North America, ranging from Southern Alaska through British Columbia, Washington, Oregon, and California into Baja California, extending east to Montana and Nevada.
Behavior
Primarily nocturnal, but often seen during the day in shaded vegetation. They are excellent climbers. When threatened, they rely on camouflage or leaping into dense cover. They are famous for their loud choruses during the rainy season.
Diet & Feeding
Insectivorous. Adults actively forage for beetles, flies, spiders, ants, and leafhoppers. They use a 'sit-and-wait' strategy or short active stalks to catch prey with their sticky tongues.
Reproduction
Breeding occurs from winter to early summer, triggered by rainfall. Males aggregate at ponds and call to attract females. Amplexus is axillary. Females lay small clusters of 10-70 eggs attached to underwater vegetation.
Vocalizations
The classic 'ribbit' or 'krek-ek' sound. It is a two-part call that is the most common frog sound in Hollywood films, regardless of the movie's setting. Chorus behavior can be deafening near breeding ponds.
Life Cycle
Eggs hatch in 2-3 weeks depending on temperature. Tadpoles are dark with flecks and take 2-3 months to undergo metamorphosis. Juveniles look like miniature adults immediately upon emerging from the water.
Conservation Status
IUCN Status: Least Concern. Populations are generally stable and they are among the most common amphibians in their range, though they face local threats from habitat loss and pollutants.
Toxicity & Defense
Not toxic to humans. They rely on camouflage (crypsis) and the ability to change color to match their surroundings. They also utilize high-frequency leaping to escape predators.
Ecological Role
High-order consumer of invertebrates and a vital food source for birds, snakes, and larger amphibians. They serve as excellent indicators of wetland health.
Similar Species
Boreal Chorus Frog (Pseudacris maculata) has three dorsal stripes; Sierran Treefrog (Pseudacris sierra) is genetically distinct but morphologically nearly identical, divided by geography.
Observation Tips
Look on the leaves of broad-leafed plants near water or in damp gardens. At night, follow the loud 'ribbit' calls. Using a flashlight to look for 'eye shine' is effective.
Handling & Safety
Safe to handle, but always wet your hands first to protect their permeable skin. Avoid handling if you have lotion, soap, or bug spray on your hands. Wash hands after handling to avoid salmonella risk.
Seasonal Activity
Active year-round in milder coastal areas; becomes more active during the winter and spring rainy seasons for breeding. May aestivate in underground burrows or logs during hot, dry summers.
Cultural Significance
Due to its Hollywood fame, its call is the universal 'Hollywood' sound for a frog. It is a symbol of spring and rain for many indigenous peoples of the Pacific Northwest.
Interesting Facts
This frog is the 'official' frog of the State of Washington. Its 'ribbit' call is so iconic that it has been used as a sound effect for frogs in movies set all over the world, including the Amazon and Southeast Asia.